The present application relates generally to unique techniques, systems, methods, and devices for the collection, release, extraction and/or detection of analytes; and more particularly, but not exclusively, relates to the composition, and other features of analyte sampling devices; methods of designing, making, and using analyte samplers; analyte sampler kitting; and related systems.
State-of-the-art detection of explosives, illegal pharmaceuticals, poisons, radioactive materials, heavy metals, and other chemically/biologically active substances, often involves trace analyte collection by physically wiping/swiping a test article surface with a swipe sampler that is submitted to on-site or remote instrumentation for analysis. Still other arrangements, such as walk-through portals, may generate/direct certain airstreams to facilitate analyte collection. Even so, such alternatives still often rely on a sampling device that is the same or at least similar to a swiping sampler to ultimately hold the collected analyte(s) until transfer/release for instrumentation processing can take place.
Accordingly, the proper collection, retention, release, handling, transfer, extraction and processing of contraband or undesirable substance traces with sampling devices is often of paramount concern. When used for transportation security screening, the sampling device should accommodate articles common to travel, which exhibit wide variation in terms of internal and external surface compositions and shapes desired to be sampled—posing significant challenges particularly to swipe sampler designers.
Current trace detection samplers are often made of a cotton material, like muslin, and submit the trace agent(s) to Ion Mobility Spectrometer/Spectroscopy (IMS) field equipment for analysis. Typically, IMS enables rapid analysis, has low detection limits for many analytes of interest, has a low operating cost, and requires little or no sample preparation. Consequently, IMS is one of the most widely used analytical methods for explosives detection throughout the world. However, IMS can produce erroneous results due to its lack of selectivity, susceptibility to interference, environmental humidity sensitivity, as well as nonlinear behaviors including, e.g., sample reproducibility issues, and human error.
Muslin cotton swipe material is often used to obtain samples for evaluation by a number of analytical instruments, such as Mass Spectroscopy (MS), thermal desorption Gas Chromatography (TD-GC), X-Ray Fluorescence (XRF), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and extracted uranium detection techniques. For IMS applications, recovery of the analyte from cotton/muslin sampling media can be accomplished by rinsing with solvents; however, it is less complicated to heat the sampling media to introduce the analyte into the IMS for subsequent assay. Unfortunately, heat-based release from cellulosic fibers, like cotton, is often constrained because these fibers have a limited thermal stability—decomposing at the relatively low temperature of about 150° C. Furthermore, unprocessed cotton sampling swabs contain non-cellulosic compounds found in the native fibers (i.e. waxes, natural oils and starches) as well as sizing agents and lubricants added for textile processing. Typically, processes used to remove these impurities in industry include mechanical scouring, chemical scouring agents, and enzymatic methods that can weaken the cellulosic fibers and make them unsuitable for repetitious use. Moreover, natural sampling materials can have variable backgrounds and variable chemical reactivity because of differences in natural growing processes and material sourcing from different geographic areas. In contrast, synthetic sampling materials, like certain polymeric coatings, can be produced under controlled conditions—minimizing background influence and variation from other sources using process control techniques. Various coatings can also improve uniformity. The decomposition of unstable swab material can release contaminants into a detection instrument and therefore interfere with the sample analysis and negatively impact the detection process. Also, high specific heat (>1.3 J/g ° C.), low thermal conductivity (˜0.24 W/m-K), and surface chemical heterogeneity of cellulosic fiber materials can adversely impact the release of analytes from the surface—concomitantly limiting detection performance.
U.S. Pat. No. 6,642,513 B1 to Jenkins et al. (the “'513 patent”), issued on 4 Nov. 2003, offers several different alternatives to muslin sampling in the form of variously configured “traps,” and is hereby incorporated by reference as if set forth in its entirety herein except to the extent the '513 patent conflicts with the present application, in which case the present application prevails. In the '513 patent, one trap type for walk-through portal applications uses directed airflow to move analytes from the subject to the trap. For this application, trap composition is stainless steel—apparently without any coating or other surface treatment. While Stainless steel was selected because of good analyte collection properties it was thought to be too abrasive for contact/swipe type applications (See the '513 patent col. 3, lines 48-63; and col. 5, line 46-col. 6, line 2). The '513 patent also specifies a polyamide fiber felt—apparently without any type of coating or other surface treatment. The '513 patent also specifies a trap having an open weave glass fiber coated by PolyTetraFluoroEthylene (PTFE). Furthermore, the coating is systematically roughened with an abrasive to cut through it and break/expose glass fibers. A scrubbing material results from the broken fibers that acts in substantially the same manner as a brush—believed to be better for analyte collection (See the '513 patent FIG. 2 and accompanying text). Moreover, coating is sparsely applied so that open spaces remain in the glass fiber web as defined by the open weave. See, for example, the '513 patent FIGS. 2 and 3 and accompanying text; and col. 2, lines 37-58.
Unfortunately, the '513 patent fails to specify or consider various salient characteristics of samplers, leaving to the imagination many aspects significant to performance. Among its shortcomings, the '513 patent proposes to improve collection by exposing glass fibers and leaving unclosed holes in the glass fiber web—potentially exposing bordering glass fibers. To the contrary, untreated glass fibers have been found to hamper the desired release of certain analyte(s) because they bind too strongly as empirically established in the description set forth hereinafter. The '513 patent is also silent as to desired thermal properties regarding analyte release by thermal desorption, glass type, and the like.
Generally, existing sampling swipes, including more rigid types, are relatively expensive and have poor thermal conductivity—typically having a relatively thick polymer (like PTFE) coating. Such configurations can impede analyte release by thermal desorption or otherwise diminish desired signal level. Current sampling techniques also fail to readily accommodate testing for certain nonstandard analytes of interest such as those associated with monitoring nuclear compliance programs and/or verifying compliance with heavy metal safety exposure standards applicable to mining and other industries. Conventionally, the sampling material needs to be digested and its chemical signature excluded from the analysis for the target analyte(s)—costing precious time and limiting the ability to obtain consistent results. Consequently, it would be desirable to have a sampling device that does not require such lengthy treatment to release analyte(s) of interest.
Improving sample collection and analyte transfer to instrumentation would likely improve sensitivity, stability, and potentially selectivity—addressing many fundamental problems presently plaguing field-deployed instruments expected to consistently detect trace analytes using conventional swipes. Indeed, existing schemes often can be cumbersome to use, and/or make it difficult to readily and consistently obtain a satisfactory result in certain instances. Accordingly, there remains an ongoing demand for further contributions in these technical arenas.
By way of transition from this background to other sections of the present application, one or more specific definitions, and any sub-definitions thereof, are set forth below and supplemented by example or further explanation where deemed appropriate. Among other things, these definitions are provided to: (a) resolve meaning sometimes subject to ambiguity and/or dispute in the applicable technical field(s) and/or (b) exercise the lexicographic discretion of any named inventor(s), as applicable:
1. “Percentage” or “percent” (%) as used herein defaults to percentage by weight of the referenced item relative to the whole (also designated by “% wt”) unless a different basis is expressly indicated.
2. “Nanoparticle” means any particle having a maximum dimension in the range of about 1 nanometer through about 1000 nanometers (nm).
3. “Fabric” broadly refers to both nonwoven and woven types. Nonwoven types include, but are not limited to: felts, knitting, braiding, plaiting, Chopped Strand Mat (CSM), velour, combinations of these, and any other nonwoven fabric type known to those skilled in the art at the time of the present application filing. Woven fabric types encompass both closed weave and open weave varieties and include, but are not limited to: plain weaves, satin weaves (including, but not limited to Harness Satin (HS) weaves and crow(s) foot weave), twilled weaves, heddle weaves, herringbone weaves, houndstooth weaves, Dutch plain weaves, Dutch twilled weaves, reverse Dutch weaves, basket weaves, Leno weaves, mock Leno weaves, gauze weaves, cross weaves, tablet weaves, DURAWEAVEs, hybrid weaves, weft-faced weaves, warp-faced weaves (backstrap weaves), gauze weaves, oxford weaves, pinpoint weaves, poplin weaves, pile weaves, knotted weaves, real weight weaves, combinations of these various weaves, and other weaves as are known to those skilled in the art. Weave patterns are typically described in terms of warp and weft, which refer to relative position of the fibers used to create the weave pattern. Typically, warp fibers refer to lengthwise fibers held in a loom while the weft fibers interlace at right angles with warp fibers. The weft fibers typically are carried with a shuttle during loom operation. The weft also may be referred to as filling, woof, and pick.
4. “Closed weave” means any weave other than an “open weave” including that referenced in the '513 patent; and/or means a weave that lacks a pre-defined pattern of one or more openings through the fabric, where each such opening is wider than any fiber element bordering the same and the weave is arranged so two adjacent fiber elements are held apart from each other to provide opening formation under nominal conditions.
5. As is known to those skilled in the art, “fiber glass” or “fiberglass” sometimes refers to Glass-Reinforced Plastic (GRP), which often includes a pultrusion of roves or other configuration of a glass in combination with an amount of organic polymer, binder, and/or resin effective to prepare a corresponding composite combination thereof. However, “fiber glass/fiberglass” is also sometimes used to refer to glass fibers without organic polymer/binder/resin constituent(s) and/or before combination with the same. This distinction occasionally relies on context—often resulting in some degree of ambiguity. In contrast, “glass fiber” is more commonly accepted to refer to fibers of glass absent/before combination with organic polymer/binder/resin constituent(s) (if ever to be so combined); and such terminology shall be used to mean the same. If the term “fiber glass” or “fiberglass” is used herein, it shall have the same meaning as “glass fiber” set forth above. Any reference to an organic polymer, binder, and/or resin in combination with “glass fiber” and/or “fiberglass/fiber glass” is expressly stated herein and/or by utilizing the “glass-reinforced plastic” (GRP) terminology.
6. “High Strength Glass” (HSG) means any non-crystalline solid composition (equivalently designated “glass” or “amorphous” composition) conforming to the following “HSG formula”: 50% wt to 100% wt of any combination of aluminosilicate, aluminum silicate, and/or alumina/silica constituents (such as, for example, Al2O3.SiO2), 0% wt to 25% wt of any combination of calcium oxide (CaO) and/or magnesium oxide (MgO), and 0% wt to 5% wt Boron oxide (such as, for example, B2O3), with any balance consisting of other constituents and/or any minor impurities. This definition includes any glass complying with the HSG formula before or after any processing, including, but not limited to: furnace heating, floating on molten material to form sheet glass, ion implantation, molten salt bath exposure, annealing, coating, or the like. This definition also means any R-glass and/or S-glass as these terms are commonly understood by those of ordinary skill in the art at the time of filing of the present application—even if not conforming to the HSG formula.
7. “Flexural modulus” is a measure of stiffness/rigidity/resistance to bending, and is defined as the result (in units of pressure) from testing in accordance with American Society for Testing and Materials (ASTM) Standard D790 of any released version in effect on or before the filing of the present application. The flexural modulus is sometimes called the “bending modulus” or the “elastic modulus;” however, these last two terms tend to be applied inconsistently to other types of moduli, test procedures, and/or contexts, so they are not used herein. Flexural modulus corresponds to an intrinsic material property subject to certain constraints/limitations—being the ratio of stress to strain in flexural deformation as obtained by a three-point test per ASTM D790. This test applies force to a beam of the material under test as it rests on two supports. The test force is applied on the opposite side from the support contacts and at is positioned therebetween. The test beam has a specified span (length) to depth ratio and is believed to reduce or eliminate the influence of extrinsic factors (such as shapes that might impart different degrees of stiffness) during otherwise uniform the test results. For the purpose of the present application, to the extent the material under test includes reinforcing fibers that extend a greater distance (on average) along a specified direction, the beam shall be prepared so that such direction coincides with the beam span—applying the test force approximately perpendicular to and across these fibers. To the extent the fibers extend approximately the same distance in multiple directions (as with a generally planar fabric), any of these directions may be oriented to coincide with the beam span for testing purposes. Flexural modulus is similar to Young's modulus in some respects and the two sometimes have values that are well within an order of magnitude or for the same material (both in units of pressure); however, flexural modulus has become a common industry alternative to Young's modulus for synthetic organic polymers and composites because these types of materials tend to have certain properties for which Young's modulus may not prove as readily obtainable, informative, or applicable. To provide a few examples of flexural modulus, consider the following approximations: (a) PTFE<0.5 GigaPascal (GPa); (b) 25% wt glass-filled PTFE≈1.3 GPa; (c) cardstock>2.7 GPa; (d) Polyvinylchloride (PVC)≈3.3 GPa; (e) Gold<4.5 GPa; and (f) 20% wt glass-filled polycarbonate≈5.5 GPa as based on a literature search (citations omitted).
8. “Metal” means any elemental metal, with or without any minor impurities therein, and any metal alloy (defined below).
9. “Metalloid” refers to any of the following elements: aluminum, antimony, arsenic, astatine, boron, carbon (as further defined hereinafter), germanium, polonium, selenium, silicon, tellurium, or combination thereof, with or without minor impurities therein. A carbon metalloid includes any allotrope of carbon, but excludes any carbon atom to the extent it is an atomic constituent in an organic compound recognized as such in any International Union of Pure and Applied Chemistry (IUPAC) reference to organic nomenclature in effect on or before the filing of the present application. To dispel any doubt, aluminum is considered both a metal and a metalloid for the purposes of the present application.
10. “Metal alloy” means a compound comprised of a combination of two or more different metals, a combination of at least one metal and at least one metalloid, or any combination thereof, either with or without minor impurities.
11. “Inorganic metallic material” means: (1) any inorganic substance with at least a majority of the following properties: malleability; ductility; electrical conductivity; thermal conductivity; ability to melt and/or fuse two or more portions of such substance together; shiny appearance/metallic luster to the extent not covered with a coating, compound, oxide, or other constituent altering visual appearance of the same; and/or (2) any inorganic substance with one or more metals and/or metalloids alone or as an atomic constituent of a salt, compound, molecule, complex, adduct, composite, anion, cation, or other combination with a nonmetal and/or a non-metalloid atomic constituent. Accordingly, inorganic metallic material includes, but is not limited to: any metal, metalloid, or metal oxide, and any glass, ceramic, or glass-ceramic having a metal or metalloid atomic constituent. To dispel any doubt, inorganic metallic material does not include any organometallic substance.
12. “Heavy metal” means certain metals and metalloids that have the potential to seriously impact the environment (including flora and fauna, among other things) and/or the safety of humans including: arsenic, cadmium, mercury, lead, chromium, copper, zinc, nickel, selenium, silver, antimony, thallium, beryllium, and cobalt in any elemental form with or without minor impurities; and/or any combination or metal alloy thereof.
13. “Contraband or undesirable substance” means any potential nefarious, illegal, dangerous, or threat agent listed in the '910 patent (in its text and/or accompanying figures), and/or any substance that belongs in one or more of the following categories: (a) explosives; (b) illegally trafficked drugs; (c) chemical or biological warfare agents; (d) nerve agents; (e) pesticides; (f) pharmaceutical process contaminants; (g) environmental toxins; (h) heavy metals; (i) actinides; (j) radioisotopes of any element with the potential to seriously impact the environment (including flora and fauna, among other things) and/or human safety; and/or (k) a salt, compound, molecule, complex, metal alloy, combination, analogue, homologue, isomer, equivalent, adduct, derivative, hydrate, composite, and/or stimulant of any substance listed in the '910 patent (in accompanying text and/or figures), and/or belonging to any of categories (a)-(j).
14. “Ammonium” broadly means any substance that includes: (a) an ammonium cation (referring to the general structure NH4+, for example); (b) like-charged amine including any such amine with primary, secondary, tertiary, or quaternary substituents; and/or (c) any salt, combination, compound, molecule, complex, equivalent, analogue, homologue, adduct, and/or, composite of any of the substances of the foregoing listings (a) and (b). In contrast, any reference to the chemical formula NH4+ for the cation alone or as part of another formula, such as (NH4)2CO3, shall be limited to the meaning of such formula and equivalents thereto as understood by those of ordinary skill in the art at the time of filing of the present application.
15. “Onium” broadly means any substance comprising: (a) ammonium; (b) a cation formed by protonation (hydron addition) of a mononuclear parent hydride of: the nitrogen family (periodic table group 15), the oxygen family (periodic table group 16), or the halogen family (periodic table group 17); (c) derivatives formed by substitution of any cation of the above-listed parent substances of (a) & (b) by univalent groups, (the number of substituted hydrogen may be indicated by the adjectives primary, secondary, tertiary or quaternary); (d) derivatives formed by substitution of any cation of the above-listed parent substances of (a)-(c) by groups having at least two free valencies on the same atom; (e) independent of the meanings conveyed under the foregoing listings (a)-(d), onium cations shall also encompass any meaning conveyed by the onium nomenclature that follows in this listing, where such nomenclature has the meaning that would be understood by those of ordinary skill in the art at the time of filing of the present application unless expressly stated to the contrary: alkanium, alkenium, alkynium, alkonium, alkenonium, alkynonium, arenium, amidium, (including carboxamidium, for example) oxonium (refers to any oxygen cation with three bonds, including, but not limited to: hydronium, oxocarbenium, alkoxonium, triethyloxonium, methyloxonium, trimethyloxonium, trialkoxonium, oxatriquinane, and oxatriquinacene, for example), nitrenium (refers to NH2+ or more generally R2N+, for example), nitrilium (refers to any cation formed by protonation of a nitrile as represented by R—C≡N+H or R—C+═NH, where “R” is a functional group, or alkylation of a nitrile [RCNR′]+, where “R” and “R′” are functional groups, for example), nitronium (refers to NO2+ formed by protonation of nitric acid or removal of an electron from the nitrogen dioxide molecule, for example), nitrosonium (refers to NO+ and organic derivatives thereof, for example), iminium (refers to a protonated or substituted imine cation of the general structure [R1R2C═NR3R4]+, where R1, R2, R3 and R4 are functional groups, for example), iminyhum (refers to the general structure R2C═N+, where R is a functional group, for example), nitrylium, carbonium (refers to any cation that has a pentavalent carbon atom or a carbon atom of greater valency/coordination number, including but not limited to: methanium (CH5+), ethanium (C2H7+), alkanium, and any organic derivative thereof, for example), carbenium (refers to a molecule with a trivalent carbon atom or three-coordinate carbon atom that bears a +1 charge, and any organic derivative thereof, for example), carbynium (refers to the radical H2C.+ and any organic derivative thereof, for example), arsonium, stibonium, halonium, selenonium, fluoronium, chloronium, bromonium, borenium, telluronium, iodonium, bismuthonium, germonium, stannonium, plumbonium, boronium, silanium, hydrogenonium (refers to trihydrogen cation or protonated diatomic/molecular hydrogen, for example), hydrohelium, kryptonium, xeonium, phosphonium, sulfonium, aminodiazonium, hydrocyanonium, diazonium, pyridinium, pyrylium, hydrazinium, diazenium, silylium, and mercuronium; (f) any substance with multiple “onium” cation groups, such as a double onium ion, a triple onium ion, and greater onium ion multiples (+2, +3, and greater charge, respectively) where “onium” complies with any meaning of the foregoing listings (a)-(e); and/or (g) any salt, complex, compound, molecule, combination, adduct, hydrate, equivalent, analogue, and/or homologue of any of the substances of the foregoing listings (a)-(f). From a theoretical standpoint, onium compounds/cations are counterparts to “ate” complexes/anions—such anions often being polyatomic. Further, onium cations and ate anions can combine to form a wide range of commonly available/known salts.
16. “Carbonate” broadly means: (a) any salt or ester of carbonic acid or carbamic acid; (b) a carbonate anion (CO32−), bicarbonate anion (HCO3−), polyvalent percarbonate anion species including both a carbonate anion moiety and an oxide anion moiety, divalent peroxocarbonate anion (CO42−), divalent peroxodicarbonate anion (C2O62−), monovalent hydrogenperoxocarbonate anion (H—O—O—CO2−), or carbamate anion (CH2NO2−), where it is understood that two or more of the carbonate, bicarbonate, and carbamate anion species may coexist at equilibrium in solution under certain circumstances; (c) a carbonate, bicarbonate, subcarbonate, percarbonate, peroxocarbonate, peroxodicarbonate, or sesquicarbonate anion constituent; and/or (d) any salt, complex, compound, molecule, combination, adduct, hydrate, equivalent, analogue, and/or homologue of any of the substances of the foregoing listings (a)-(c). In contrast, any reference to the chemical formula CO32− for the anion alone or as part of another formula, such as (NH4)2CO3, shall be limited to the meaning of such formula and equivalents thereto as understood by those of ordinary skill in the art at the time of filing of the present application.
17. “Thickness” refers to the smallest dimension of an object unless expressly indicated to the contrary herein. By way of example, thickness refers to the distance between opposing sides of a generally planar sampler, where such opposing sides have a length and width much greater than such distance (thickness). To the extent thickness is quantitatively specified herein, it is determined as the average of ten (10) measurements taken at ten (10) different locations along the object using a measurement device having a rated accuracy of +/−0.01 millimeter (mm) or better. As used herein, ‘thin” means at least a portion of an object under measurement has a thickness of less than or equal to 0.3 mm determined in accordance with such measurements. As a corollary, to the extent used herein an object is “thick” if it is not “thin” such that its thickness dimension is determined to be >0.3 mm as determined by measurements according to the procedure listed above. These definitions of thin and thick supersede any definition of like terms set forth in the '910 patent and/or the '513 patent.
18. To “calcine” (also calcined/calcining/calcination and the like) generally refers to heating a subject material in an enclosure at a selected temperature to remove a volatile fraction, desiccate, reduce, oxidize, and/or otherwise selectively change the subject material, and may be performed with or without control of air, oxygen, or other gas content in the enclosure in its broader form. By way of nonlimiting example, for a composite subject material, heating temperature may be selected above the melting point of a polymer constituent (but not exceeding its decomposition temperature) while remaining below the melting point of a glass fiber fabric constituent to which the polymer is applied. The selected temperature completely or partially melts the polymer constituent, changing its morphology to promote the formation of longer polymeric molecules or “chains” and/or interconnection between the same under certain circumstances, while the glass fabric is only negligibly impacted if at all (but note polymer coverage of the fabric and the polymer-glass interface may be subject to change by in this calcination example). At the same time, calcining may at least partially remove any volatile fraction present after certain liquid-based application of the polymer to the fabric (even with pre-calcination evaporation), and/or desiccate all of the constituents as a function of constituent composition, heating temperature selected, and/or heating duration. Because calcination and roasting in a metallurgical/material science context are sometimes compared, it should be appreciated that roasting is generally performed at a considerably higher temperature than calcination for a given material—where roasting typically heats an ore to promote one or more gas-solid reactions that improve metal component purity of/from the ore.
The above listing of one or more definitions/sub-definitions apply to any reference to the corresponding subject terminology herein unless explicitly set forth to the contrary. Any acronym, abbreviation, or terminology defined in parentheses, quotation marks, or the like shall have the corresponding meaning imparted thereby through the present application unless expressly stated otherwise herein.